// +build ignore,OMIT package sample // OMIT func run() (err error) { in, err := os.Open(*input) if err != nil { return err } defer in.Close() out, err := os.Create(*output) if err != nil { return err } defer func() { // HL if cerr := out.Close(); err == nil { // HL err = cerr // HL } // HL }() // HL // some code }